According to new research, great white sharks can’t tell the difference between their regular meal and humans swimming or paddling on surfboards, implying that some shark attacks are cases of mistaken identification.
Researchers watched seals and humans in the ocean and altered the footage to mimic the eyesight of juvenile great white sharks, often known as white sharks, which pose the biggest threat to human surfers. From the perspective of a shark, the shape and movements of people resemble those of seals.
The study, which was published in the Journal of the Royal Society Interface on Tuesday (Oct. 26), is the first to put to the test the idea that sharks attack humans because they mistake us for prey.
According to the University of Florida’s International Shark Attack File, great white sharks are responsible for more human deaths than any other shark species, killing six people in 2020, even though the relative chance of humans being bitten by sharks remains extremely low.
When these sharks reach a length of 8.2 feet, they begin hunting seals. To determine what to eat, they create a search picture for their prey and integrate it with other sensory information, such as scent. It’s a learning process that might lead to errors.
Great white sharks do not have color vision and cannot perceive minute details like humans. The researchers likened the movements of humans swimming and paddling on surfboards to how a shark’s retina recognizes the motion and forms of seals. This contained a longboard surfboard that measured 9.3 feet by 1.9 feet and a shortboard surfboard that was 5.8 feet by 1.6 feet. They concluded that none of the circumstances were visually distinguishable for a juvenile great white shark swimming beneath.
The longboard surfboard was less comparable to seals, indicating that a great white shark may perceive the form of longboard surfboards differently from shortboard surfboards and swimmers. However, the researchers are unsure how this is mirrored in shark behavior because sharks bite humans on longboards as well, according to Ryan.
The current study only relates to great white sharks; other sharks, such as bull sharks and tiger sharks, attack people on occasion. Furthermore, according to Ryan, adult great white sharks occasionally bite humans, and as they are older, more experienced hunters, they may make fewer mistakes.
In other words, not all bites are the result of a misidentification. According to the International Union for Conservation of Nature, great white sharks are on the verge of extinction, and people actively kill them as part of beach protection initiatives in Australia and South Africa, however, the sharks are sometimes trapped and returned alive.
According to Ryan, not knowing why sharks attack humans causes public worry, which leads to humans implementing steps to lower shark numbers, which hurts other marine species. Sharks perform vital roles in ocean ecosystems, and by eating other creatures, they guarantee that prey populations remain healthy and at a size that their habitat’s resources can sustain, as previously reported. Ryan thinks that gaining a better knowledge of why sharks bite humans would lead to better ways for reducing shark attacks without endangering marine species.